Method of making a heat transfer device

ABSTRACT

The heat transfer system includes a plurality of wound tube coils fixed within the holes of at least three plates disposed in a radiating axial manner from the axis of the system. The tube coils are wound helically or spirally and are fixed at three points about the holes through which they pass.

United States Patent [191 Kaelin 111 4 3,742,567 [451 July 3,1973

' METHOD OF MAKING A HEAT TRANSFER DEVICE 75] inventor: Werner Kaelin,La .lolla, Calif.

[73] Assignee: Sulzer Brothers Limited, Winterthur,

Switzerland 221 Filed: Sept. 25, 1970 211 App]. No.: 75,4 0

7 Related US. Application Data [62] Division of Ser. No. 626,453, March28, 1967, Pat.

3,080,916 3/1963 Collins 29/l57.3 B X 3,274,755 9/1966 Montagnon et a1.1 55/269 1 3,286,767 11/1966 Evans 165/163 X 2,204,614 6/1940 Nelson eta1. 29/1573 B 3,545,534 12/1970 Coles et a1. 165/67 FOREIGN PATENTS ORAPPLICATIONS 146,399 8/1954 Sweden 1. 165/172 157,156 10/1939 Austria165/172 520,071 4/1940 Great Britain 914,083 12/1962 Great Britain165/172 920,836 3/1963 Great Britain 165/163 Primary ExaminerCharles W.Lanham Assistant Examiner-D. C. Reiley, lll Attorney- Kenyon 8L KenyonReilly (arr & (Thapin [57] ABSTRACT The heat transfer system includes aplurality of wound tube coils fixed within the holes of at least threeplates disposed in a radiating axial manner from the axis of the system.The tube coils are wound helic'ally or spirally and are fixed at threepoints about the holes through which they pass. I

3 Claims, 12 Drawing Figures PATENTED JUL 3 I975 smears Inventor- WERNERKAELIN BY I ,4 TTOPNEVS PATENTEUJULS I975 SHEEI 3 BE 3 .N w murs v m m MWERNER METHOD OF MAKING A IIEAT TRANSFER DEVICE This is a division ofapplication Ser. No. 626,453, filed Mar. 28, 1967, now Pat. No.3,616,848.

The invention relates to a method of making a heat transfer device. Moreparticularly, the invention relates to a method of making a heattransfer assembly including a cluster of at least one helically orspirally wound tube.

I-leretofore, heat transfer systems of the above kind have had the tubecoils fixed spatially by bands and screws. However, this construction aswellas the methods for attaching such has been complicated and very timeconsuming and as a result has been expensive.

Briefly, this invention provides a heat transfer system having a clusteror plurality of tubes at least one of which is helically or spirallywound into a tube coil and a plurality of plates which mount the coilsof the tube coils and which are disposed radially of the coils andaxiallyof the tube cluster. The plates are provided with holes throughwhich the coils of a tube coil pass and are provided with locking meansfor fixing the coils within the plates.

In one embodiment of the invention, a wedge is inserted at the locationswhere the coils pass through the plates between a pair of adjacent tubecoils i-n wedging relation to the coils and rigidly connected, as bytack welding, to the adjacent plate. Similar wedges are secured to eachplate between each pair of tube coils so that only one wedge on a plateis used or each pair of tube coils thereby reducing the number ofwedges.

In another embodiment of the invention, the tube coils pass throughwedge-shaped holes in the plates and contact with two spaced pointsaround the hole. Also, a wedge is secured at one end to a-plate anddisposed in wedging relation to a tube coil passing through the holes ofthe plate. This effects a three point support for each tube passingthrough a plate while maintaining the initial stress between the wedgeand tube. In the event that a tube coil should become loosened the playbetween the tube and any of the three points of support is slight.

In another embodiment, each of two adjacent wedgeshaped holes aredisposed with the board ends in facing relation and a wedge is wedgedbetween the tubecoils passing through these holes. Thisenables twoadjacent tubes to be fixed by a single wedge so that each tube has athree point support. This embodiment can be further modified byenlarging each pair of facing wedge-. shaped holes so as to form asingle slot and by wedging a single wedge between the pair of tube coilspassing through the slot. This modification allows a reduction in weightof the plates without affecting the securement of the tube coils in theplates.

In still another embodiment, the sides-of the holes or slots whichcontact the tube coils are formed with outwardly bent flaps which aredisposed out of the plate plane and bear resiliently on a tube coil toprevent loosening of the tubes. These flaps bear against the tube coileven during variations in temperature. Likewise, the wedges are formedwith resilient flaps which extend transversely to the plane of thewedges to bear resiliently on the tube coils.

Preferably, the angle between the bearing surface of a wedge and thewedge side of the hole adjacent to the narrow end of the wedge is morethan twice the angle of friction.

In still another embodiment, the relative positions of the plates arealtered with respect to each other after insertion of the tube coilseither by altering the angular positions of the plates or the axialpositions through the use of the fixing means. In this embodiment; thewhole tube cluster is fixed in the plates 'with one adjusting movement.Alternatively, the relative positions of the tube coils can be alteredafter insertion in the plates to resiliently fix the tube coils inplace. This is accomplished by positioning a bar axially of'the tubecluster between radially adjacent tube coils in resilient engagementwith the coils. Advantageously, the bar can have recesses into whicheach coil fits. The bar is secured in place by being welded to across-bar which is fixed to the plates at their point of intersection.

The method provided by the invention includes the steps of securing aplurality of apertured plates to gether to form a radiating platestructure, coiling at least one straight tube into a helical winding,and inserting the coiled portions of the tube through the apertures ofthe plates in a helical manner. A -further method of the inventionincludes a simultaneous coiling and insertion through the apertures ofthe plates of the tube in a single operation.

Accordingly, it is an object of the invention to provide a heat transfersystem having tube coils which are fixed in place in a singleinexpensive manner.

It is another object of the invention to provide a wound tube coil in aplurality of radiating plates.

It is another object-of the invention to support a tube coil in aplurality of plates with a three point support in each plate. I

It is another object of the invention to position a wound tube coil in aplurality of radiating plates in a resilient manner.

These and other objects and advantages of the invention will become moreapparent from the following detailed description and appended claimstaken in conjunction with the-accompanying drawings in which:

FIG. 1 illustrates an elevational view of a heat transfer systemaccording to the invention,

FIG. 2 illustrates a plan view of the system of FIG. 1; FIG. 3illustrates a section through a means for fixing the tubes of a heattransfer system of the invention in 1 place;

FIG. 4 illustrates a fragmentary section through a modified means forfixing the tubes in place;

FIG. 5 illustrates a bar which is used in fixing tubes in placeaccording to the invention;

FIG. 6 illustrates a fragmentary view of a heat trans- I fer systemusing the bar. of FIG. 5 to fix the tubes in place;

I ll of a modified heat transfer system of the invention;

FIG. 11 illustrates a view taken on line C-D of FIG. 10; and- I FIG. 12illustrates a view taken on line E-F of FIG.

Referring to FIGS. 1 and 2, heat transfer system 1 consists essentiallyof pairs of tube coils 2, 3 of different radii and plates, for example,four plates 4, 5, 6, 7 which are disposed substantially at right anglesto each other to mount the tube coils. The plates 4, 5, 6, 7 areweldedtogether at the center of the heat transfer system 1 and radiatetherefrom axially of the system. Each plate 4, 5, 6, 7 has a pluralityof fully encompassed apertures or holes in the plane of the plate whichare of radii corresponding to the radii of the tube coils 2, 3' so as topermit passage of a tube coil with a relatively clost fit. In addition,these holes are spaced in accordance with the coil intervals of the tubecoils 2, 3. Wedges are secured to all the plates 4, 5, 6, 7 to wedgebetween the coils not only of the outer tube coil 2 but also the innerconcentric tube coils 3 to fix the tube coils 2, 3 in the plates. Forexample, wedges 9 are inserted between each pair of coils of tube coil 2near to the locations of the passage of the coils through the plate 4and are secured, as by tack welds, to the plate 4 so as to fix the tubecoil 2 in the plate 4. Similarly, wedges 8 are secured at one end toplate 7 and pass between the coils of the tube coil 2.

Referring to FIG. 3, instead of using wedges, the tube coils (only twoof which are shown for clarity) pass through holes in the plate 7 aswell as through a pair of aligned holes in a fork 40 which is slidablymounted over plate 7. The fork 40 has a threaded screw 42 which passthrough the top into abutment with the top surface of plate 7 for movingthe fork 40 up and down relative to plate 7. The fork 40 and screw 42are dimensioned so that when the screw 42 is threaded outwardly of thefork 40 so as to permit the fork 40 to rest directly on the plate 7, theholes in the fork 40 and the holes in the plate 7 are coincidental. Thecoils of the tube coils can then be passed through these holes. However,when the screw 42 is threaded inwardly of the fork, the fork 40 movesupwardly of the plate 7 causing a misalignment of the respective holes.Thus, with the coils passing through the holes in the plate 7 and fork40 and the screw being tightened to raise the fork, the walls of theholes in the fork and the wall of the hole in the plate bear against thecoils to fix the tube coils in place. Similar fork-type fixing means aremounted on each plate over each vertical set of holes therein and-eachscrew of a fork is screwed simultaneously into the fork when the coilsof the tube coils are passing through the plates. Alternatively, a forkcan be dimensioned to pass over a. number of vertical sets of holes inthe plates to grip and fix several radially juxtaposed coils.

Referring to FIG. 4, the plates instead of being fixed together at acommon intersection point are constructed to pass one through the other.In such a case, a screw 1] is threaded into a threaded bore in a portion10 connecting the opposite plates 4, 6 to contact the upper surface ofthe connecting portion between the remaining plates 5, 7. Upon insertionof the tube coils in the aligned holes of the respective plates, thescrew 11 is tightened to shift plates 4 and 6 angularly relative to theremaining plates 5 and 7 as well as axially so as to fix the tube coilswithin the holes of the plates 4, 5, 6, 7.

Referring to FIG. 5, another means for fixing the tube coils in theplates consists of a bar 15, which has recesses 16 along its length ontwo opposite sides. These recesses are adapted to the radii of the tubesof the tube coils, and the distance a between them corresponds to thetube coil intervals. The distance b between the recesses 16 is greaterthan the radial distance c between the tube coils 2 and 3. The tubecoils are fixed by first inserting the bar 15 between the coils 2 and 3,so that it is at right angles to the position shown in FIG. 6. When thebar 15 is situated at the correct height, it is turned about itslongitudinal axis, so that the recesses l6 bear on the tube coils 2 and3. Because the distance b is greater than the distance 0, the tube coils2 and 3 are braced resiliently in a radial direction, and pressed firmlyagainst the hole walls in the plates 6 and 7. The bar 15 is secured inthe position shown in FIG. 6 by welding to it a cross-bar 17, which iswelded to the plates 6 and 7 at the point where these plates meet.

Referring to FIG. 7, one method of making a heat transfer system, forexample, having a plurality of apertured plates 4, 5, 6, 7 (as describedabove) secured in a radiating manner from a displacement cylindricalbody 30 and disposed in spaced circumferential relation to each other,starts with the feeding of a straight tube 22 in the direction indicatedby arrow 21 through a series of three rollers 20. As the tube 22 isshaped into a coil of constant diameter and constant coil interval bythe rollers 20 it is fed perpendicularly (as shown) into the platesthrough the apertures in the respective plates 4, 5, 6, 7. Upon fillingthe innermost series of apertures in the plates, the next series ofapertures is filled in the same manner; the distancebetween the rollersof the series of rollers 20 being adjusted in accordance with thedifferent radius of curvature of the outer tube coil.

Referring to FIG. 8, where the tube coils are of a spiral configuration,a straight tube 25 is initially fed in the direction of arrow 24 througha roller system 26 positioned between adjacent apertured plates 4 and 7to be bent into a curvature enabling it to pass through theseconsecutive plates 4, 5 and 6. Next, the curve tube is passed throughsecond roller system 27 positioned between plates 6 and 7 to be bentinto a curvature enabling it to be passed through the following threeplates 7, 4 and 5. Finally, the curved tube is passed through a rollersystem 28 positioned between plates 5 and 6 to be bent into a curvatureenabling it to pass through plates 6, 7 and 4. This method enable a heattransfer system to be constructed with spiral tube coils which mayeither extend in a plane parallel to the plane of the drawings or lie ona conical surface.

Referring to FIG. 9, the plates of the system, for example, plate 4, isprovided with holes 48 of wedgeshaped outline for the passage of thecoils of the tube coils 2. Each pair of adjacent holes 48 are disposedwith the broad ends of the wedge-shape in facing relation. Each pair ofholes 48 cooperates with a wedge 9 which is secured at its broad end, asby welding, to the plate 4 and is disposed between adjacent coils ofpipe coil 2 to fix the coils to the plate 4. The wedge 9 is sized topress the coils through the wedge surfaces 49 toward and against thewedge sides of the holes 48 so that each coil is supported reliably atthree points. The angle-a between the wedge surface 49 and the wedgeside of a hole 48 adjacent the narrow end of wedge 9 is larger than.twice the angle of friction.

Referring to FIGS. 10 to 12, the means to fix the coils of tube coil 2in the plates. can also utilize slots 50 which have been formed frompairs of adjacent wedgeshaped holes which are interconnected throughremoval of the separating piece of the plate between them. In this case,each slot 50 has two pairs of flaps 5I 'bent from the plate 4 into'thepassage bounded by the 50 between the pairs of flaps 51 and coils and issecured as by a'tack weld 53 to the plate 4 at one end. The wedge 9. hastransversely extending flaps 52 along opposite sides which bearresiliently against the coils and cooperates with flaps 51 to supporteach coil at three points. This three point support fixes the coils inthe plate 4 in a manner toflexibly receive any heat expansion betweenthe coils and plate 4. In addition, this resilient fixing means preventsthe occurrence of pitting which is of particular advantage where theheat transfer systems are used in nuclear reactors since the wearresulting from pitting could jeopardize the operation of the reactor.

ln use, a heat conveying medium flows substantially axially around thecluster of tubes of the heat transfer systems of FIG. 1, 2, Z and 9 to12 whereas, the medium flows substantially radially through the clustersof tubes of the systems of FIG. 8.

It is noted thatthe coils of the pipe coils which carry known heattransfer mediums can be fixed to the plates of the heat transfer systemsof the invention by welding, for example, by tack welds. Further, thenumber of radiating plates used in accordance with the invention mayinclude three or more plates. and may be uniformly or non-uniformlyspaced from each other around the circumference of the system.

Having thus described the invention, it is not -intended that it be solimited as changes may be readily made therein without departing fromthe scope of the invention. Accordingly, it is intended that theforegoing Abstract of the Disclosure, and the subject matter describedabove and shown in the drawings be interpreted as illustrative and notin a limiting sense.

What is claimed is:

l. A method of making a heat transfer system having a plurality of woundtube coils fixed in a plurality of plates having fully encompassedapertures in the plane of the plates comprising the steps of v mountingthe radiating plates in a secured radiating manner with the platesdisposed in spaced circum ferential relation,

bending a straight tube to impart a curvature therein,

coiling the curved tube about itself to form a tube coil, and

inserting the tube coil perpendicularly into the plates into and throughthe apertures of the apertured plates.

2. A method as set forth in claim 1 wherein the curved tube is coiledinto a helical configuration and the helical tube coil is inserted intothe apertured plates in a helical manner.

3. A method as set forth in claim 1 wherein said steps are performedsimultaneously.

1. A method of making a heat transfer system having a plurality of woundtube coils fixed in a plurality of plates having fully encompassedapertures in the plane of the plates comprising the steps of mountingthe radiating plates in a secured radiating manner with the platesdisposed in spaced circumferential relation, bending a straight tube toimpart a curvature therein, coiling the curved tube about itself to forma tube coil, and inserting the tube coil perpendicularly into the platesinto and through the apertures of the apertured plates.
 2. A method asset forth in claim 1 wherein the curved tube is coiled into a helicalconfiguration and the helical tube coil is inserted into the aperturedplates in a helical manner.
 3. A method as set forth in claim 1 whereinsaid steps of coiling and inserting are performed simultaneously.